Plugin.Maui.DocumentScanner 0.2.0

Plugin.Maui.DocumentScanner

Native document scanning for .NET MAUI — no paid SDK required.

dotnet add package Plugin.Maui.DocumentScanner

• Android: ML Kit document scanner (full scanner UI, auto-crop, filters; models downloaded via Google Play services)
• iOS: VisionKit document camera for scanning, plus Vision document segmentation with a built-in corner editor for cropping already-taken photos

Supports Android API 23+ (with Google Play services) and iOS 15+.

Setup

Register the plugin in MauiProgram.cs:

builder
    .UseMauiApp<App>()
    .UseDocumentScanner();

UseDocumentScanner() registers IDocumentScanner in dependency injection and hooks the Android activity-result plumbing — no MainActivity changes needed.

iOS: camera permission

ScanAsync opens the camera, so add a usage description to Platforms/iOS/Info.plist — iOS terminates the app without it:

<key>NSCameraUsageDescription</key>
<string>Scan documents with the camera.</string>

ScanFromPhotosAsync uses the system photo picker and needs no photo-library permission.

Android

No permissions or manifest changes are required. ML Kit downloads its scanner module through Google Play services on first use, so the first scan on a device can take a few seconds longer.

Usage

Inject IDocumentScanner (or use DocumentScanner.Default without DI):

// Camera scan — returns file paths of cropped pages, empty list if the user cancels
IReadOnlyList<string> pages = await scanner.ScanAsync();

// iOS only: pick already-taken photos, then adjust each crop in the corner editor.
// On Android this throws NotSupportedException, so guard it.
if (OperatingSystem.IsIOS())
    pages = await scanner.ScanFromPhotosAsync();

// With options
pages = await scanner.ScanAsync(new DocumentScanOptions
{
    PageLimit = 3,
    Mode = DocumentScannerMode.Base, // Android only: Full, BaseWithFilter, or Base
});

// With cancellation — dismisses the native UI and throws OperationCanceledException
using var cts = new CancellationTokenSource(TimeSpan.FromMinutes(2));
pages = await scanner.ScanAsync(cancellationToken: cts.Token);

Check scanner.IsSupported first. On Android ScanAsync throws NotSupportedException when ML Kit reports the device is unsupported (under ~1.7 GB RAM).

Returned files are JPEGs written to the app's cache directory — move or copy them if you need them to persist.

Platform notes

Sample

The samples/ScanTest app exercises both scan paths and shows page sizes and timings. To deploy it to a physical iPhone, copy ScanTest.local.props.example to ScanTest.local.props and fill in your signing identity.

Changelog

See CHANGELOG.md.